Desmond geeald fitz-geeald



ggh'assesaisw ---anode feather-electrolytic generation of chlo- -iu rna enecnot;

UNITED STATES PATENT. ()FFIcE.

DESMOND GERALD FITZGERALD, OF AKERMAA ROAD, LOUGHBOROUGH ROAD, BRIXTON, COUNTY OF SURREY, ENGLAND.

oerammc CH LORINlZ-BY ELECTRO-LYSIS.

SPECIFICATION forming part of Letters To all 10750122, it may concern:

Be it known that I, DEsMoNn'Gnni Ln FIrz-I GERALD, a subject of the Queen of Great Britain, residing at 6 Akermau Road, Loughbor- 1a b 1. 9.351.BliKtQU,jlLtheeconntylof Surrey,- 5 England, electrician, have invented certain new and useful Improved Means for Efl'ectiug the Electro-Chemical Generation of Chlorine in Metallurgical} Operations for the Extraction 10 of Gold'from its Ores-and for other Purposes, of which the following is a specification.

" The great diificnlty in the electrolytic generation of chlorine by the decomposition uuder the influence of an electric current of hy- 15 drochloric acid or of an alkaline or earthy chloride in solution has been to find a suitable anode unacted upon by the gas in its nascent condition. One material only-via, carbon, a usually in the form known as gas carbon- 26 has h eentsrailahletcruse .on a large j scale in'the above operation.------.lhismaterial, however, is far from'fulfilling the condition of being unacted upon chemically and mechanic ally by the evolved chlorine. k5 disintegration of the carbon anode, together with the difliculty of establishing efiieient electrical contact between fragments or plates of this material, has led to the failure in practice of electrolytic processes for the extraction of o the-precious-metalsfronrtheir 'oresTby means of chlorine and for the utilization of this elemeutin various other directions.

Now, I have foimd that peroxideof lead in V tile-firm lea .QQAdustireplMes,layers, or

rs admirably the purpose of an rine. Being already in the highest condition of oxidation, it is not liable to further action noris-it' actednipon by the 0 hypochlorites, or liable to disintegration by the efi'ect of the nascent chlorine evolved from any case found necessary to insure the permanency of such plates, layers, or masses when 4 5 employed as anodes is, when free hydrochloric acid is contained in the electrolyte, to avoid the prolonged contact of the peroxide with this acid when the current is no longer pass- I ing. 50 In the accompanying drawing, in section,

The ultimate Patent No. 357.659, dated February 15, 1887. Application filcdifictober 18,1886. Serial Nmillfififli. (No model.)

A Ais a tank of slate or of brick lined with suit; able material; B B, anode of llead peroxide; C, contact-piece of platinum; D D, cathode of copper forming a tray, of which the outer snrface is coated with insulating material; E, ore '5 to be acted upon by chlorine; F, electrolyte. -l" In carrying my invention into effect for the t purpose of extracting gold from its ores and for other metallurgical purposes, I usually co n I strnct anodes of large surface, applied to 0- supported by a portion of the interior su MG.

of an electrolytic tank in such manner that he.

ore to be treated may be in contact with t and may thus be permeated by sulphate or chloride of ammonium-which will more or less gradually and partially .r'eact upon the lead compound to produce a'chemical change, causing the composition to set and to acquire a high degree of solidity. I thus avoid any admixture with the lead com pound of inert materialsuch as plaster-ofparis or other ce1nentwhich would render impossible the ultimate production of a highly conductive mass of peroxide of lead. I have constructed anodes wholly of this composition, applied by means of a trowel, while yet freshly mixed, to a portion of the interior surface (as shown inthe accompanying figure) of an electrolytic tank; but by reason of the effects sometimes produced by the'very considerable ex pansion which occurs during its conversion into peroxide I prefer to employ this composition merely as a kind of mortar, by means of whichl build up the anode by uniting together slabs, plates, fragments, or granules of peroxide of lead, or of an insoluble compound of lead more or less superficially converted into peroxide of lead.

The course I usually adopt, therefore, in the construction of anodes of large surface is, first, to produce slabs, plates, tiles, or granules of the compositions hcreinabove described, 10o

mixture with a solution-such as that of the by compressing in suitable molds the freshlyniixed plastic mass composed of oxide of lead (litharge)with (for instance) a half-saturated solution of sulphate of ammonia, or with a solution of hydropotassic sulphate (sal-onixum) peroxide of lead by the passage of a current through the mass when it has obtained a suf- .ficient degree of hardness and solidity. In effecting the electrolytic conversion last mentioned, I prefer to employ as the electrolyte dimtesulplmricacidorasoluuon of the sulphate of soda or of magnesia. Oontactwith the anode material may be obtained by means of a plate of platinum embedded in the upper portion of i the mass and any suitable cathode-such asa .plate Of'c'opper-may be, employed to complete the circuit of the dynamo-machine or other source of electricity used to efle'ct the conversion of v the material into peroxide. ,When this conversion has been efl'ected to a isuflicient' extent-i. e., when the whole surface brown color,

of theanode has'acqui red a darkabsorbing the oxygen and-evolves in lieu of (liberated by the passage of the current-the above-mentioned electrolyte may be replaced b e h oride-Solut on generation .of chlorine. 7

1;, I have given as an example onejmodeingwhich peroxide of lead maybe utilized, ac-' ;cording to my invention, forthe electro-chemical generation of chlorine on a large scale, and I have indicated the only known means, so far as I am aware, by which indestructible anodes iof this material-that is, slabs, plates, "or

:massesnotliableto disi n teg rationnot-i-ncon-- tact with any oxidizable (conducting) support,

o he mplqyedinthe.

and possessing a sufliciently high degree of conductivity to allow of the conducting support being dispensed with, may be readily obo tained; but ll do not confine myself to the above-described mode of utilizing peroxide of lead as an anode which is convenient and effective in the treatmentof ores or compounds containing gold; nor do I limit myself to the 5 precise modes of obtaining peroxide of lead in a coherent form, which have been referred to. It is obvious that in the'electro-chemical generation of chlorine for bleaching purposes, or for the manufacture of hypochlorites or of 6 chlorates, a series of vertioallydisposed plates of peroxide of lead alternating with cathode-- plates of any suitable conducting material may conveniently be employed, and it is possible toobtain suchplates by various means, 6 which, according to my experience, are less convenient and effective than those whichhave been indicated above. Again, it is not essential in all cases to obtain contact with the peroxide by-means of platinum. For instance, 7 the vertically-disposed plates just mentioned may be connected together and. with an external conductor by means of an alloy fusible at a comparatively low temperature, such alloy being subsequently protected from electro- 75 chemical action by means of a layer of cement.

What I claim as my invention 'is-' v The electrochemical generation of chlorine by means of an anode of peroxide of lead in the form of dense highly conductive layers, 80

plates, or masses of any required form, preferably obtained by the means hereinbefore described, the said anode being employed in con'- junction with any suitable cathode and with an electrolyte capable of evolving chlorine.

5 In testimony whereof I, the said DESMOND GERALD FITZ-GERALD, have hereunto set my hand this 12th day of August, 1886.

DESMOND GERALD Fl'lZ'GERAhD. Witnesses:

G. F. WARM-1N,

Notary Public, VVALTER J. SKERTEN, Both of 17 Graccchurch St, London. 

